Mapping systems that provide direction information and location of various registered locales are commonly utilized. Map making has largely been carried out by visitors to a particular place. The knowledge of places acquired by these visitors was then aggregated and assimilated. The person with the best available knowledge of a particular area was in a superior position when it came to conquest, settlement, or trade. As the world was discovered, knowledge of its geography gradually spread to more and more people and maps improved. As technology advanced, so did the accuracy of mapmaking until arriving at what today is generally agreed upon as maps of the world.
Many location-based applications, such as yellow pages or social mobile applications use maps to communicate location to users. In contrast, maps cannot be used as part of text-based or voice-based communication, such as a Short Message Service (SMS), on a phone, or while driving. Textual addresses can be slow to perceive due to their lengths, require significant cognitive effort, and may fail if the user requesting the information is unfamiliar with the area.
When people communicate locations to each other, they often base their descriptions on mutually known landmarks. For example, people can agree to meet in a certain place or can discuss having spent the first night of their backpacking trip at “the hotel in Agra, Northern India, a mile north of the Taj Mahal”.
In contrast, computer programs communicate location using more formal, canonical presentations. Global Positioning Systems (GPS) typically express location as pairs of latitude and longitude. Car navigation systems use a lookup table to translate the latitude/longitude pair into street addresses. Thus, instead of suggesting meeting at a particular place, such as in front of the Ritz Carlton, a navigation system will refer to “2801 Main St., City, State”. The Indian location may turn into “XX Street, India”. Unfortunately, these formal representations are often not the best way of communicating a location. First, parsing a formal address tends to take time and effort. Secondly, the communication may fail entirely if the person receiving the location information does not know the city and streets involved in the address.
Understanding a formal address requires users at the receiving end to parse the address into their own reference system. In some situations, that reference system can be a system of landmarks. Communicating a notation using the receiver's landmarks can speed up the process by bypassing this conversion. For example stating, “The conference center is located at the corner of Main Street and Third Street” typically requires more processing than “two blocks north of the conference hotel”. This is also useful for navigation tasks that involve spatial relationships between the involved locations, such as the decision whether to walk or take a taxicab.
The situation where the receiver does not know the cities and streets is generally the case for unfamiliar or foreign cities. For cities with which the receiver is familiar, in many ways, cities and streets are just particular, commonly agreed on sets of landmarks. The grid layout (e.g., plus mnemonic street names, such as 5th Ave., and the use of the first two digits of a street address to indicate the cross street) used by many United States cities can make it easier to locate an address. However, street navigation in Europe and many other parts of the world requires substantial local street knowledge and therefore it can fail more often.